Pain Perception Research Articles

Assessing Gender Differences in Neuropathic Pain Management: Findings from a Real-Life Clinical Cross-Sectional Observational Study

Introduction: Neuropathic pain is defined as pain induced by a lesion or disease of the somatosensory nervous system. Pharmacological and non-pharmacological treatments are frequently employed. In the current clinical investigation, we assessed the effects of sex on the safety and effectiveness of medications used to treat neuropathic pain. Methods: We conducted a prospective analysis between 1 February 2021 and 20 April 2024, involving patients with neuropathic pain referred to the Ambulatory of Pain Medicine of “Renato Dulbecco” University Hospital in Catanzaro (Calabria, Italy). Patients over 18 years old with signs of neuropathic pain (Douleur Neuropathique en 4 questionnaire ≥ 4) were included. Exclusion criteria comprised patients with Alzheimer’s disease; patients with nociplastic or nociceptive pain; and patients with neoplasms. Patients with fewer than two accesses to ambulatory care were excluded, as were those who did not sign the informed consent. Clinical data were collected from each enrolled patient and subsequently analyzed, considering clinical outcomes. Sex and gender differences in efficacy were estimated using multivariate linear modeling and propensity-score matching. Results: During the study, 531 patients were screened, and 174 were enrolled (33.5%, mean age 61.5 ± 13.1; 64 males and 110 females, mean age 60.6 ± 13.4 and 61.96 ± 13.0) in accordance with the inclusion and exclusion criteria. Only minor differences in treatment prescription were observed based on age, body mass index, and comorbidities. Smoking, sex, educational level, and body mass index did not induce a significant change in pain perception. Males required slightly higher, though not significantly, doses of drugs for pain control than females. The treatment was not significantly more effective for females than for males. Females did not exhibit a significantly lower number of adverse drug reactions compared to males. Conclusions: The current study found that there are no appreciable differences between the sexes when it comes to the treatment of neuropathic pain.

Psychedelics as novel therapeutic agents for chronic pain: mechanisms and future perspectives

Chronic neuropathic pain is a significant public health issue affecting an estimated 1.5 billion individuals worldwide. The mechanisms underlying chronic pain are multifaceted and not fully understood. Chronic pain amplifies specific neural pathways through peripheral and central sensitization triggered by repeated exposure to noxious stimuli, ultimately resulting in physical and emotional pain. Traditional treatment options targeting these mechanisms, such as opioid and non-opioid analgesics, are associated with adverse effects, addiction, and suboptimal pain relief. Using psychedelics to treat chronic pain is an area of growing interest. While psychedelic substances, such as psilocybin, lysergic acid diethylamide, mescaline, and 3,4-methylenedioxymethamphetamine are primarily associated with recreational use or spiritual practices, emerging evidence suggests their potential therapeutic benefits for various mental health disorders, including chronic pain. Psychedelics alter pain perception by directly activating serotonin receptors, exerting anti-inflammatory effects, enhancing descending inhibition, opening a window of neuroplasticity, and facilitating synaptic remodeling. This review mainly elucidates the ongoing research regarding the psychedelic mechanisms of action, pharmacology, clinical applications, and therapeutic potential in treating neuropathic pain.

Effect of Preemptive Analgesia on Pain Perception in Children: A Randomized Controlled Trial.

Efforts have been made to minimize pain, prevent the development of needle fear, and promote positive experiences for children. The present study is designed to evaluate the effect of premedication with Ibugesic Plus before the administration of local anesthesia and extraction in children. The aim of the study is to assess the efficacy of preemptive analgesia on pain perception during local anesthesia administration and extraction in pediatric patients. A total of 104 patients aged 7-10 years were selected who needed primary molar extraction. Group -Ibugesic Plus syrup was given 30 minutes prior to extraction. Group II-Placebo solution (B-Folcin syrup) was given 30 minutes prior to extraction. Pain level, pulse rate, and SpO2 were assessed using the Wong-Baker Faces Pain Rating Scale (WBFS) and pulse oximeter after injection, after extraction, and postoperatively. The highest scores of pain were recorded after the time of injection and extraction. The patients who received preemptive analgesics (group I) reported significantly less pain than the placebo group (group II) at the time immediately after injection, after extraction, and 2 hours after extraction. The present study showed that preemptive analgesic administration may be considered a routine and rational pain management strategy in primary tooth extraction procedures in children. Preemptive analgesia can be given to patients prior to dental procedures to reduce postoperative pain. Virda M, Panda A, Kataria K. Effect of Preemptive Analgesia on Pain Perception in Children: A Randomized Controlled Trial. Int J Clin Pediatr Dent 2024;17(8):913-917.

The role of diurnal variation in development of musculoskeletal pain during prolonged standing

BackgroundResearch suggests mechanical changes occur to the body over the course of the day including shrinking of the intervertebral disc height which can increase rotational stiffness and rigidity of the spinal column. Further, pain sensitivity has been observed to fluctuate throughout the day, suggesting variations in pain sensitivity. Previous work has identified biomechanical and neuromuscular features related to the development of musculoskeletal pain during prolonged standing; however, many protocols have not controlled for time of day. Research questionDoes the time of day (i.e., diurnal variation) have an effect on the common neuromuscular and biomechanical variables characterizing the development of standing musculoskeletal pain in a two-hour prolonged standing protocol? MethodsA convenience sample of 20 healthy young adults (10 female and 10 male) completed two 2-hour prolonged standing bouts (8:00 a.m. and 8:00 p.m.) on separate days. Visual analogue scales were used to measure pain perception of the low back, legs, and feet throughout each protocol. Neuromuscular control was measured using surface EMG on muscles of the trunk and lower extremities. Postural sway was captured using measures of joint range of motion, and the analysis of center of pressure trajectory data using a force plate. ResultsDiurnal variation was observed to influence the development of musculoskeletal pain. Specifically, pain perception was found to be increased in the evenings as more participants were classified as pain developers in the PM sessions, and mean leg and foot pain perceptions were higher in the evening. Reduced postural sway patterns, and elevated co-contraction indices were found to be associated with the development of pain. SignificanceThese results suggest that future research assessing standing-pain protocols should control for time of day. Additionally, further research is warranted to explore the mechanistic causes of the development of standing pain.

Pain perception during intravitreal injections is related to the timing of instilling anesthetic eyedrops

Pain perception during intravitreal injections is related to the timing of instilling anesthetic eyedrops

Application Value of Iodine-131 Combined with Levothyroxine Sodium in Patients with Differentiated Thyroid Cancer after Surgery

Introduction: This study aimed to evaluate the clinical value of iodine-131 combined with levothyroxine sodium in the treatment of patients with differentiated thyroid cancer (DTC) after surgery. Methods: Prospective randomized controlled studies were conducted. A total of 374 DTC patients who underwent total or near-total thyroidectomy in the Department of Thyroid Surgery, Tianjin Union Medical Center and Tianjin Medical University General Hospital, from January 2019 to February 2022 were selected and divided into control group (187 cases) and observation group (187 cases) according to random number table method. The control group was treated with levothyroxine sodium after surgery, and the observation group was treated with iodine-131 on the basis of the control group. Gender, age, course of disease, tumor diameter, pathological type, TNM classification, treatment effect, thyroglobulin (Tg) levels before and after treatment, SF-36 health status questionnaires (SF-36), occurrence of adverse reactions after treatment, and recurrence rate of 1-year follow-up were compared and analyzed between the two groups. Results: There was no significant difference in baseline data between the two groups. After treatment, the effective rate of the observation group increased by 11.23% compared to the control group, with a statistically significant difference (91.98% vs. 80.75%, p < 0.05). There was no significant difference in Tg level and scores of SF-36 evaluation including physical functioning, physical problems, vitality, pain, mental health, emotional problems, social functioning, and general health perception between the two groups before surgery (p > 0.05), Tg levels and scores of SF-36 evaluation in all dimensions were significantly improved in both groups after treatment (p < 0.05), and the levels of Tg and scores of SF-36 in all dimensions in observation group were significantly better than those in control group after treatment (p < 0.001). There was no significant difference in the incidence of adverse reactions between the two groups (p > 0.05). The recurrence rate in the observation group was 5.89% lower than that in the control group 1 year after treatment, with a statistically significant difference (2.67% vs. 8.56%, p < 0.05). Conclusions: The combination of iodine-131 and levothyroxine sodium in the postoperative treatment of DTC can improve the therapeutic effect and reduce the postoperative recurrence rate without increasing adverse reactions, which is worthy of clinical reference and promotion.

Effects of Stress Exposure to Pain Perception in Pre-Clinical Studies: Focus on the Nociceptin/Orphanin FQ-NOP Receptor System.

Exposure to physical and psychological stress modulates pain transmission in a dual manner. Stress-induced analgesia (SIA) refers to the reduction in pain sensitivity that can occur in response to acute stress. On the contrary, chronic stress exposure may lead to a phenomenon named stress-induced hyperalgesia (SIH). SIH is a clinically relevant phenomenon since it has been well documented that physical and psychological stress exacerbates pain in patients with several chronic pain syndromes, including migraine. The availability of animal models of SIA and SIH is of high importance for understanding the biological mechanisms leading to these phenomena and for the identification of pharmacological targets useful to alleviate the burden of stress-exacerbated chronic pain. Among these targets, the nociceptin/orphanin FQ (N/OFQ)-N/OFQ peptide (NOP) receptor system has been identified as a key modulator of both pain transmission and stress susceptibility. This review describes first the experimental approaches to induce SIA and SIH in rodents. The second part of the manuscript summarizes the scientific evidence that suggests the N/OFQ-NOP receptor system as a player in the stress-pain interaction and candidates NOP antagonists as useful drugs to mitigate the detrimental effects of stress exposure on pain perception.

Nociception Coma Scale-Revised with Personalized Painful Stimulus Versus Standard Stimulation in Persons with Disorders of Consciousness: An International Multicenter Study.

Background/Objectives: Persons with disorders of consciousness (DoCs) may perceive pain without being able to communicate their discomfort. The Nociception Coma Scale (NCS) and its revised form (NCS-R) have been proposed to assess nociception in persons with DoCs. The main aim of this international multicenter study was to confirm (or not) our preliminary results and compare the NCS-R scores of standard stimulus (NCS-R-SS) to scores of personalized painful stimuli (NCS-R-PS). A secondary aim of the study was to verify possible correlations between the NCS-R-PS and Coma Recovery Scale-Revised (CRS-R) and to estimate convergent validity. Methods: Sixty-one patients with prolonged DoCs (pDoCs) were enrolled from seven European post-acute rehabilitation centers. Responsiveness and pain perception were assessed by CRS-R and NCS-R with standard stimulus (NCS-R-SS) and personalized stimulation (NCS-R-PS). ClinicalTrials.gov Identifier: NCT06012357. Results: our results support our prior findings on the superiority and the validity of the personalized painful stimulus approach in assessment of pain in persons with DoCs in comparison with the standardized pain assessment methodology. Conclusions: A more in-depth and tailored assessment of pain perception in persons with a DoC may lead to better acknowledgment of its presence and by extension an objective foundation for more aggressive and appropriate pain management.

Non-surgical nursing care for tumor patients: an overview of sedation, analgesia, and recent innovations.

With the increasing prevalence of tumors, effective symptom management has emerged as a cornerstone of patient care. While surgical interventions remain pivotal, non-surgical nursing methods have gained prominence in providing relief from pain, discomfort, and other tumor-related symptoms. This review delves into the various non-surgical approaches employed, emphasizing tumor sedation and analgesia. We discuss the array of non-pharmacological and pharmacological strategies, shedding light on their indications, contraindications, and potential side effects. Furthermore, the importance of addressing individual differences in pain perception and the ethical considerations in symptom management are highlighted. We conclude by providing insights into the recent innovations in the field, emphasizing the need for personalized and comprehensive care to enhance patients' quality of life. Tumor sedation, Tumor analgesia, Non-surgical nursing care, Pain management, Non-pharmacological interventions, Palliative care, Recent innovations, Symptom management.

Exploring the role of Yuxuebi tablet in neuropathic pain with the method of similarity research of drug pharmacological effects based on unsupervised machine learning.

Having multiple pharmacological effects is a characteristic of Traditional Chinese Medicine (TCM). Currently, there is a lack of suitable methods to explore and discover modern diseases suitable for TCM treatment using this characteristic. Unsupervised machine learning technology is an efficient strategy to predict the pharmacological activity of drugs. This study takes Yuxuebi Tablet (YXB) as the research object. Using the unsupervised machine learning technology of drug cell functional fingerprint similarity research, the potential pharmacological effects of YXB were discovered and verified. LC-MS combined with the in vitro intestinal absorption method was used to identify components of YXB that could be absorbed by the intestinal tract of rats. Unsupervised learning hierarchical clustering was used to calculate the degree of similarity of cellular functional fingerprints between these components and 121 marketed Western drugs whose indications are diseases and symptoms that YXB is commonly used to treat. Then, based on the Library of Integrated Network-based Cellular Signatures database, pathway analysis was performed for selected Western drugs with high similarity in cellular functional fingerprints with the components of YXB to discover the potential pharmacological effects of YXB, which were validated by animal experiments. We identified 40 intestinally absorbed components of YXB. Through predictive studies, we found that they have pharmacological effects very similar to non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroids. In addition, we found that they have very similar pharmacological effects to anti-neuropathic pain medications (such as gabapentin, duloxetine, and pethidine) and may inhibit the NF-κB signaling pathway and biological processes related to pain perception. Therefore, YXB may have an antinociceptive effect on neuropathic pain. Finally, we demonstrated that YXB significantly reduced neuropathic pain in a rat model of sciatic nerve chronic constriction injury (CCI). Transcriptome analysis further revealed that YXB regulates the expression of multiple genes involved in nerve injury repair, signal transduction, ion channels, and inflammatory response, with key regulatory targets including Sgk1, Sst, Isl1, and Shh. This study successfully identified and confirmed the previously unknown pharmacological activity of YXB against neuropathic pain through unsupervised learning prediction and experimental verification.

Exploring the Activation Process of the Glycine Receptor.

Glycine receptors (GlyR) conduct inhibitory glycinergic neurotransmission in the spinal cord and the brainstem. They play an important role in muscle tone, motor coordination, respiration, and pain perception. However, the mechanism underlying GlyR activation remains unclear. There are five potential glycine binding sites in α1 GlyR, and different binding patterns may cause distinct activation or desensitization behaviors. In this study, we investigated the coupling of protein conformational changes and glycine binding events to elucidate the influence of binding patterns on the activation and desensitization processes of α1 GlyRs. Subsequently, we explored the energetic distinctions between the apical and lateral pathways during α1 GlyR conduction to identify the pivotal factors in the ion conduction pathway preference. Moreover, we predicted the mutational effects of the key residues and verified our predictions using electrophysiological experiments. For the mutants that can be activated by glycine, the predictions of the mutational directions were all correct. The strength of the mutational effects was assessed using Pearson's correlation coefficient, yielding a value of -0.77 between the calculated highest energy barriers and experimental maximum current amplitudes. These findings contribute to our understanding of GlyR activation, identify the key residues of GlyRs, and provide guidance for mechanistic studies on other pLGICs.

UNRAVELING THE GENETIC AND BIOLOGICAL INTRICACIES OF ANESTHESIA FOR CHRONIC PAIN: A COMPREHENSIVE REVIEW OF COMT GENE VARIATIONS AND THEIR IMPACT ON TREATMENT EFFICACY ACROSS ETHNICITIES

Chronic pain management remains a significant challenge, with individual responses to anesthesia and analgesics varying widely due to genetic and biological factors. This review explores the influence of the catechol-O-methyltransferase (COMT) gene, particularly the Val158Met polymorphism, on pain sensitivity and opioid efficacy across different ethnicities. COMT variations play a crucial role in modulating pain perception and analgesic response, with Met allele carriers generally exhibiting higher pain sensitivity and lower opioid requirements. Ethnic differences in COMT gene frequencies further impact anesthesia efficacy, underscoring the importance of personalized pain management strategies. The review also discusses the potential of pharmacogenetic approaches, a beacon of hope for improving treatment outcomes. It highlights emerging technologies in genetic-based pain management, such as epigenetic modulation and gene editing.

Patient Preferences and Expectations in Analgesia for First Trimester Surgical Abortion

&lt;i&gt;A central component of a patient’s abortion experience is pain perception and optimization of pain management choices. Yet, data on patients’ experience of pain and their preferences regarding pain strategies are limited and tend to utilize solely quantitative data. This study utilized a qualitative thematic analysis to identify patient priorities, preferences, and expectations for pain management during first-trimester surgical abortion with nitrous oxide or oral sedation. Thirty-one patients seeking a first-trimester surgical abortion, self-selecting inhaled nitrous oxide (NO) (16 patients), or oral sedation (PO) with oxycodone and Ativan (15 patients) enrolled in this prospective cohort study. Participants provided demographic data, rated procedure pain on a 10 cm visual analog scale (VAS), and participated in semi-structured interviews. We analyzed qualitative data using a content analysis approach. Pre-procedure participants wanted a positive experience. Participants endorsed an ideal analgesic as having a quick onset of action, minimal side effects, no addiction potential, and being effective at reducing pain. After the procedure, there we start differences between priorities in NO and PO participants. NO participants valued the resumption of everyday activities, while PO participants desired ongoing anxiolysis. Anticipatory counseling often mitigated higher procedure pain and more medication side effects than anticipated. Participants emphasized that positive interactions with providers/staff significantly improved their abortion experience. Preemptive comprehensive counseling about procedure and analgesic effectiveness, along with providing options for analgesia, will facilitate an affirmative and patient-centered abortion experience.&lt;/i&gt;

Assessing the Use of BotulinumtoxinA for Hyperactive Urinary Tract Dysfunction a Decade after Approval: A Single-Blind Study to Evaluate the Reduction in Pain in OnabotulinumtoxinA Detrusor Injection Using Different Injection Needles.

Overactive bladder (OAB) has a significant impact on the quality of life; thus, it requires treatment that can be adhered to over a long period without undue side effects. The current treatment which uses an anticholinergic or β-3 agonist may fail to improve symptoms and has side effects, leading to high discontinuation rates. OnabotulinumtoxinA (OnabotA) detrusor injection has been approved for idiopathic OAB as a second-line treatment with good effectiveness and tolerability. This study used a visual analog scale (VAS) to assess the impact of the type of needle used for OnabotA detrusor injections under local anesthesia on the pain levels after each injection. This study included 68 female patients. We used three different needles with thicknesses ranging from 22 to 27 gauge, lengths between 4 and 5 mm, and different cuts. The sensation of pain was rated at each standardized injection location. Regardless of the needle used, the patients' perceptions of pain at the beginning of the procedure were rated as being less than the subsequent injections. Most pain sensations were rated as low to moderate. The mean pain sensation on the VAS was 2.5 ± 0.3 overall, i.e., for all patients and needles used. Statistically significant differences in pain sensation were rated only at some locations of the bladder (on the back wall and the right side of the bladder). The single needles averaged the following pain scores: 2.8 ± 0.3 for needle A (20 G, 4 mm), 2.1 ± 0.3 for needle B (27 G, 5 mm), and 2.6 ± 0.4 for needle C (20 G, 4 mm, sharp cut 15°). The 27-gauge needle caused significantly less pain, and it had no negative impact due to its length, which was 1 mm longer than the other needles. Thus, the needle thickness was a decisive factor in the patients' perceptions of pain.

The relationship of pain catastrophizing in principal caregivers of postoperative children with malignant bone tumors and children's kinesiophobia and pain perception: A cross-sectional survey

ObjectiveTo examine the phenomenon of pain catastrophizing among the principal caregivers of postoperative children with malignant bone tumors and explore its impact on pain perception and kinesiophobia in children. DesignA cross-sectional study design. MethodsUsing a cross-sectional study design, a questionnaire-based survey was conducted among 140 children with malignant bone tumors and their principal caregivers, who were admitted to a tertiary hospital in Shanghai from 2020 to 2023. Pearson's univariate and multiple regression analyses were conducted. The questionnaire included general data, the Parental Pain Catastrophizing Scale, the Short-Form McGill Pain Questionnaire, and the Tampa Scale of Kinesiophobia. ResultsThe frequency of pain catastrophizing for the principal caregivers was 16.8%. The frequency of kinesiophobia in children was 93.1%. The level of pain catastrophizing was positively correlated with the level of kinesiophobia and pain perception (r = 0.556, 0.614, p < 0.05). Multiple logistic regression analysis showed that the level of pain catastrophizing in principal caregivers was an important factor of kinesiophobia in children (B = 0.370, Std. = 0.119, Wald = 9.687, Ex (P) = 1.448, p = 0.002). Multiple linear regression analysis showed that the incidence of pain catastrophizing and the level of kinesiophobia were important influencing factors in pain perception (p < 0.05), with R2 = 0.272, adjusted R2 = 0.249, F = 11.579, and p < 0.001. ConclusionsThe level of pain catastrophizing in the principal caregivers was an important factor in postoperative kinesiophobia and pain perception in children with a malignant bone tumor. Practice implicationsIt is important to evaluate the patients' and their families' emotional changes and psychological needs during the perioperative period. Nurses play a crucial role in providing appropriate interventions for patients or families to reduce the negative pain experience and improve patients’ prognosis.

Mental Health and Quality of Life of Patients with Differentiated Thyroid Cancer Pre and Post Radioactive Iodine Treatment: A Prospective Study.

Background: Although patients with differentiated thyroid cancer (DTC) have a good prognosis, their long-term clinical course can influence their mental health and their health-related quality of life (HRQoL). However, few studies have evaluated the psychological factors that influence subsequent HRQoL in this population, particularly during the initial treatment stage. Methods: In this 1-month cohort study, we evaluated depressive and anxiety symptoms and HRQoL of patients with DTC and examined possible predictors of further HRQoL impairment. Results: In total, 181 patients completed questionnaires where they self-rated their psychological status (the Chinese Health Questionnaire [CHQ], Taiwanese Depression Questionnaire [TDQ]) and HRQoL (the 36-item Short Form Health Survey [SF-36]) at baseline and 1 month after radioactive iodine (RAI) therapy. Compared with the general Taiwanese population, patients with DTC reported a worse HRQoL in all dimensions of the SF-36. Multivariate regression models indicated that anxiety and depressive symptoms were inversely correlated with some dimensions (physical functioning, bodily pain, and general health perceptions for the CHQ; role limitations due to physical problems and social functioning for the TDQ). However, psychiatric follow-up and treatment history were significantly associated with physical functioning and role limitations owing to the physical problem dimensions of HRQoL. Conclusions: In conclusion, although anxiety and depressive symptoms may negatively affect certain HRQoL domains, psychiatric follow-up can improve the physical dimensions.

Discovery of Dual TRPA1 and TRPV1 Antagonists as Novel Therapeutic Agents for Pain.

Pain management remains a major challenge in medicine, highlighting the need for the development of new therapeutic agents. The transient receptor potential ankyrin 1 (TRPA1) and vanilloid 1 (TRPV1) are ion channels that play key roles in pain perception. Targeting both TRPA1 and TRPV1 simultaneously with dual antagonists offers a promising approach to pain relief. In this study, we investigated a series of hybrid analogs of TRPA1 and TRPV1 antagonists to discover novel therapeutic agents for pain. Among these compounds synthesized by a condensation reaction forming 1,2,4-oxadiazole between the A- and C-regions, compound 50 exhibited substantial dual-acting antagonism to TRPA1 and TRPV1 with IC50 values of 1.42, 2.84, 2.13, and 5.02 μM for hTRPA1, mTRPA1, hTRPV1, and rTRPV1, respectively. In the formalin test, compound 50 demonstrated dose-dependent analgesic activity with an ED50 of 85.9 mg/kg in phase 1 and 21.6 mg/kg in phase 2, respectively, and was able to inhibit pain behavior completely at a dose of 100 mg/kg. This study presents the discovery and characterization of a novel dual TRPA1/TRPV1 antagonist, highlighting its potential as a therapeutic agent for pain management.

A computational mechanism of cue-stimulus integration for pain in the brain.

The brain integrates information from pain-predictive cues and noxious inputs to construct the pain experience. Although previous studies have identified neural encodings of individual pain components, how they are integrated remains elusive. Here, using a cue-induced pain task, we examined temporal functional magnetic resonance imaging activities within the state space, where axes represent individual voxel activities. By analyzing the features of these activities at the large-scale network level, we demonstrated that overall brain networks preserve both cue and stimulus information in their respective subspaces within the state space. However, only higher-order brain networks, including limbic and default mode networks, could reconstruct the pattern of participants' reported pain by linear summation of subspace activities, providing evidence for the integration of cue and stimulus information. These results suggest a hierarchical organization of the brain for processing pain components and elucidate the mechanism for their integration underlying our pain perception.

Association of the Serotonin and Kynurenine Pathways as Possible Therapeutic Targets to Modulate Pain in Patients with Fibromyalgia.

Fibromyalgia (FM) is a disorder characterized by widespread chronic pain, significant depression, and various neural abnormalities. Recent research suggests a reciprocal exacerbation mechanism between chronic pain and depression. In patients with FM, dysregulation of tryptophan (Trp) metabolism has been identified. Trp, an essential amino acid, serves as a precursor to serotonin (5-HT), a neuromodulator that influences mood, appetite, sleep, and pain perception through the receptors 5-HT1, 5-HT2, and 5-HT3. Additionally, Trp is involved in the kynurenine pathway, a critical route in the immune response, inflammation, and production of neuroactive substances and nicotinamide adenine dinucleotide (NAD+). The activation of this pathway by pro-inflammatory cytokines, such as tumor necrosis factor α (TNF-α) and interferon gamma (IFN-γ), leads to the production of kynurenic acid (KYNA), which has neuroprotective properties, and quinolinic acid (QA), which is neurotoxic. These findings underscore the crucial balance between Trp metabolism, 5-HT, and kynurenine, where an imbalance can contribute to the dual burden of pain and depression in patients with FM. This review proposes a novel therapeutic approach for FM pain management, focusing on inhibiting QA synthesis while co-administering selective serotonin reuptake inhibitors to potentially increase KYNA levels, thus dampening pain perception and improving patient outcomes.

Epidemiology of Canine Wei Syndrome and Its Hemorheology Characteristics.

Canine paraplegia is a common condition in small animal medicine, referred to as Wei Syndrome (WS) in Traditional Chinese Veterinary Medicine (TCVM). Common clinical manifestations encompass hind limb paralysis, motor dysfunction, muscle atrophy, and the absence of pain perception. WS is considered a difficult-to-treat disease in small animal practice. The objective of this study was to investigate the epidemiology of canine WS and the characteristics of hemorheology. A total of 53 dogs with WS and 53 healthy dogs were included in this study. A retrospective case-controlled study design was employed. Data regarding the gender, season of WS occurrence, breed, and age of dogs with WS, as well as hemorheology from dogs with WS and healthy dogs, were collected and analyzed using SPSS 27.0. The study findings revealed that male dogs were more susceptible to WS (77.36%, 41/53). WS cases occurred more frequently in Winter (33.96%, 18/53), and were commonly found in Poodle breeds (43.40%, 23/53). The most affected age of WS was between 3 and 6 years old (54.72%, 29/53). Except for plasma viscosity and fibrinogen, the hemorheology indices of canine WS were significantly higher than those of healthy dogs (p < 0.05), especially in male dogs, Poodles and Bulldogs, those between 3 to 10 years, and in Autumn and Winter. This study provides evidence that male Poodles and Bulldogs aged 3 to 6 years are more prone to developing WS, with Winter being the season of high disease incidence. Abnormal hemorheology is a characteristic feature in dogs with WS, which should be considered during the treatment of WS.